/**
 * Useful Types
 */
export declare type ArrayOrNone<T> = Array<T> | null | undefined;
/**
 * Compare functions
 * -----------------
 * Functions that compares two array elements as specified by
 * the Array sort function.
 */
export declare type CompareFunction<T> = (e1: T, e2: T) => number;
declare function compareNumbers(e1: number, e2: number): number;
declare function compareStrings(e1: string, e2: string): number;
/**
 * isEqual
 * -------
 * Compares two arrays for equality. By default the order is ignored.
 */
declare function isEqual<T>(a1: Array<T>, a2: Array<T>, compareFunction: CompareFunction<T>, ignoreOrder?: boolean): boolean;
export declare const ArrayUtils: {
    compareNumbers: typeof compareNumbers;
    compareStrings: typeof compareStrings;
    isEqual: typeof isEqual;
};
export {};